Sleep Apnoea and Neruomuscular Respiratory Disorders Flashcards
What is obstructive sleep apnoea syndrome characterised by?
- Recurrent episodes of upper airway obstruction leading to apnoea during sleep
- Usually associated with heavy snoring
- Typically unrefreshing sleep
- Daytime somnolence/sleepiness
- Poor daytime concentration
What 3 factors can lead to repeated closure of the upper airway?
- Muscle relaxation
- Narrow pharynx
- Obesity
What doe repeated closure of the upper airway lead to?
- Oxygen desaturation
- Snoring
- Apnoeas and hypopnoeas
What do apnoeas and hypopnoeas lead to?
Frequent micro-arousals
What do frequent micro arousals lead to?
- Daytime hypersomnolence
- Poor concentration
What problems can result from OSAS?
- Impaired quality of life
- Marital disharmony
- Increased risk of RTAs
- Associated with hypertension, increased risk of stroke and probably increased risk of heart disease.
What is the prevalence of OSAS?
- 2% of men
- 1% of women
How is OSAS diagnosed?
-Clinical history and examination
Epworth Questionnaire
-Overnight sleep study
What is measured in polysomnography?
- Oronasal airflow
- Thoracoabdominal movement
- Oximetry
- Body position
- EEG
- Audiovisual recording
- EOG
- EMG
- ECG
What are the categories of desaturation rate?
0-5 normal
5-15 mild
15-30 moderate
>30 severe
How is sleep apnoea treated?
- Identification of exacerbating factors
- Continuous positive airways pressure (CPAP)
- Madibular repositioning splint
How can identification of exacerbating factors help?
- Weight reduction
- Avoidance of alcohol
- Diagnose and treat endocrine disorders
What is the advice on driving?
- Advise not to drive or restrict driving and inform the DVLA of their condition
- Once satisfactorily treated should be allowed to drive
What is the prevalence of narcolepsy?
0.05%
What is narcolepsy associated with?
- Familial
- HLA DRB1*1501
- HLA DQB1*0602
What are the clinical features of narcolepsy?
- Cataplexy
- Excessive daytime somnolence
- Hypnagogic hallucinations
- Sleep paralysis
What is the treatment for narcolepsy?
- Modafinil
- Clomipramine (for cataplexy)
- Sodium oxybate (xyrem)
What is chronic ventilartory failure characterised by?
- Elevated pCO2 (>6.0kPA)
- pO2< 8kPA
- Normal blood pH
- Elevated bicarbonate
What is the aetiology of chronic ventilator failure?
-Airways diseases
-Chest wall abnormalities
-Respiratory muscle weaknesses
Central hypoventilation
Examples of airway diseases (3)
- COPD
- Bronchiectasis
- OSA
Examples of a chest wall abnormality.
Kyphoscoliosis
Examples of respiratory muscle weaknesses (2)
- Motor neurone disease (ALS)
- Muscular dystrophy
Examples of central hypoventilation (2)
- Obesity hypoventilation syndrome
- Central hypoventilation syndrome
What are the typical symptoms of chronic ventilatory failure?
- Breathlessness
- Orthopnoea
- Ankle swelling
- Morning headache
- Recurrent chest infections
- Disturbed sleep
What are the findings on examination of an individual with chronic ventilatory failure?
- Reflects underlying disease
- Paradoxial abdominal wall motion in suspected neuromuscular disease
- Ankle oedema (hypoxic cor pulmonale)
What are the investigations if neuromuscular disease is suspected?
- Lung function
- Assessment of hypoventilation
- Fluoroscopic screening of diaphragms
What lung function tests should be carried out?
- Lying and standing VC
- Mouth pressure/ SNIP
What is involved in the assessment of hypoventilation?
- Early morning ABG
- Overnight oximetry
- Transcutaneous CO2 monitoring
How does the pulmonary function results of someone with chronic ventilatory failure compare to a normal individual?
- Decreased FEV1
- Decreased FVC
- Increased FEV/FVC%
- Decreased PI max
- Decreased PE max
What is the treatment for chronic ventilatory failure?
- Domiciliary non invasive ventilation (NIV)
- Oxygen therapy
- t-IPPV
